CN110276709B

CN110276709B - Method for generating and identifying protective document and information management system

Info

Publication number: CN110276709B
Application number: CN201910527739.0A
Authority: CN
Inventors: 周晓明
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-18
Filing date: 2019-06-18
Publication date: 2022-06-28
Anticipated expiration: 2039-06-18
Also published as: CN110276709A

Abstract

The invention provides a method for generating and identifying a protective document and an information management system, which comprises the steps of obtaining a document to be protected in an electronic format; determining a foreground image of a document to be protected based on the document to be protected, calculating an MD5 value of the document to be protected in an electronic format, converting the MD5 value into a background image, and respectively acquiring pixel point information of the foreground image and the background image; based on a CMYK printing color mode, overlapping pixel points of a foreground image and a background image to generate an identification image, and expressing the pixel points of the identification image by utilizing CMYs synthetic color and K color; outputting the document with the identification image with the printing apparatus. The background image is hidden in the foreground image, so that the hiding of the anti-counterfeiting mark is realized, the anti-counterfeiting application and identification of the document can be realized based on the technology, and the closed loop of document generation and use is realized, so that the condition that the document cannot be identified due to counterfeiting and tampering is avoided.

Description

Method for generating and identifying protective document and information management system

Technical Field

The invention relates to the technical field of anti-counterfeiting, in particular to a method for generating and identifying a protective document and an information management system.

Background

In the information age, the conventional identification method of the authenticity of the document mainly comprises a seal of a document issuing mechanism, a watermark made on a printed material by using an editing tool such as WORD and the like. At present, because of the popularization of computer technology, PS seals are not difficult, and the watermark making by using a document editing tool becomes a necessary skill for secretary; on the other hand, the using environment of the document is in an open-loop or semi-open-loop state, that is, the document issuing party and the use related party are not in the same system, so that the true validity of the document for the using party cannot be conveniently proved and identified by adopting other methods except the conventional method. Therefore, the above situation objectively forms opportunities and loopholes for illegal and even illegal use of documents, which easily results in information misuse, judgment errors and economic disputes.

For example, the content of the document may be tampered with due to benefit driving, so as to meet the requirement of a certain party on the benefit; some unqualified document issuing mechanisms still illegally issue documents and cannot be found in time, so that documents which should have no efficacy are used as functional documents, and risks are brought to users.

Disclosure of Invention

The invention provides a method for generating and identifying a protective document and an information management system.

In one aspect, the present invention provides a method of generating a protective document, the method comprising the steps of:

s1: acquiring a document to be protected in an electronic format;

s2: determining a foreground image of the document based on the document to be protected, calculating an MD5 value of the document to be protected in an electronic format, and converting the MD5 value into a background image;

s3: based on a CMYK printing color mode, overlapping pixel points of a foreground image and a background image to generate an identification image, and expressing the pixel points of the identification image by utilizing CMYs synthetic color and K color;

s4: outputting the document with the identification image with the printing apparatus.

In a specific embodiment, the foreground image includes a LOGO of a document issuing authority to be protected, and the background image further includes a signature of an issuer. The document has the characteristic of uniqueness by utilizing the content setting of the foreground image and the background image.

In a specific embodiment, the four corners of the identification image are provided with L-shaped boundary identifications for automatic identification. By means of the setting of the L-shaped boundary mark, the positioning can be more conveniently realized during the generation and the identification of the mark image.

In a preferred embodiment, the identification image document is in TIF format.

In a specific embodiment, a specific representation manner of a pixel point of the identification image is as follows:

expressing white pixel points of the intersection of the foreground image and the background image by using gray synthesized by CMY;

utilizing black synthesized by CMY to represent that pixel points in the foreground image are black and the pixel points corresponding to the pixel points in the background image are white;

black pixel points of the intersection of the background image and the foreground image are represented by black of K color;

and expressing that the pixel points in the background image are black and the pixel points corresponding to the pixel points in the foreground image are white by utilizing the gray of the color K.

In a particular embodiment, the printing device comprises a color inkjet printer or a color laser printer. The printing output of the identification image can be realized by using a common color printer, and the printing cost is greatly reduced.

According to a third aspect of the present invention there is provided a method of authentication for a protective document, the method comprising the steps of:

carrying out standardized processing on the imaging of the identification image on the document to be identified under infrared illumination to obtain a background image in the identification image;

converting the current document into an electronic format, calculating the MD5 value of the document, comparing the MD5 value with the MD5 value in the background image, and judging whether the contents of the document are consistent;

Carrying out similarity contrast between the background image restored under infrared light and the original background image, and calculating similarity values of the background image and the original background image;

the document to be authenticated is true only if the MD5 values are consistent and the similarity value is greater than the similarity threshold.

According to a third aspect of the present invention, a computer-readable storage medium is proposed, on which a computer program is stored, which computer program, when being executed by a computer processor, is adapted to carry out the above-mentioned method.

According to a fourth aspect of the present invention, there is provided an information management system comprising:

a client: configured for document management using the method described above;

an image acquisition terminal: the method comprises the steps that imaging of an identification image on a document to be identified under infrared illumination is subjected to standardized processing, and a background image in the identification image is obtained;

the remote server side: configured to authenticate the document as authentic using the method described above;

the client and the image acquisition terminal are respectively connected with the remote server.

In a specific embodiment, the image acquisition terminal comprises an infrared camera, and an infrared LED light supplement lamp is arranged on the infrared camera. The background image hidden in the identification image can be identified by utilizing the infrared camera, so that the anti-counterfeiting identification effect is realized.

In a preferred embodiment, the wavelength of the infrared camera is more than 1000nm, and the wavelength of the infrared LED fill light is more than 1000 nm.

In a specific embodiment, the infrared camera is connected with a mobile phone or a computer to display an infrared image. All information in the identification image can be intuitively obtained by connecting the mobile phone or the computer.

The invention utilizes the printing color mode of CMYK to superpose two independent images together to form an identification image, so that a foreground image such as LOGO of a mechanism can be seen under a common light source, and a background image can not be seen; under infrared illumination, background images such as handwritten signatures and MD5 values of file contents are seen, but foreground images are not seen. Meanwhile, the superposed identification image can be printed at one time only by using common color printing equipment, a new protection measure is provided for the document issued by a protective document issuing mechanism, the document can be identified according to the technology, a closed-loop information management system is formed, and the management control on the authenticity of the document is more effectively carried out.

Drawings

The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain the principles of the invention. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

FIG. 1 is a flow chart of a method for the generation of a protective document of one embodiment of the present invention;

FIG. 2 is a schematic illustration of an overlay of a logo image according to a specific embodiment of the present invention;

FIG. 3 is a flow chart of an authentication method for a protective document according to one embodiment of the invention;

FIG. 4 is a schematic image of a logo image under different illumination in accordance with a specific embodiment of the present invention;

FIG. 5 is a block diagram of an information management system of one embodiment of the present invention.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the related invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

Fig. 1 shows a flow chart of a generating method for a protective document according to an embodiment of the invention. As shown in fig. 1, the method comprises the steps of:

S101: and acquiring the document to be protected in an electronic format. The electronic format of the document to be protected can be Word, PDF and other formats.

S102: determining a foreground image of the document to be protected based on the document to be protected, calculating an MD5 value of the document to be protected in an electronic format, converting the MD5 value into a background image, and respectively acquiring pixel point information of the foreground image and the background image.

In a specific embodiment, for the same document, the foreground image is relatively fixed and has consistent content, such as LOGO of a publishing organization; the background image is different from page to page, such as the issuer of the presentation, the MD5 value, etc., so that it has sufficient randomness. Inputting handwritten signatures through a handwriting board to form document signing and issuing information images; the MD5 value of the current page document content is automatically calculated and converted into an image, and a basis for identifying whether content modification is performed is formed, so that the document content is prevented from being tampered. And combining the handwritten signature image and the MD5 value image, and adjusting the size of the handwritten signature image and the MD5 value image according to the dimension parameter appointed by the identification image until the handwritten signature image and the MD5 value image are matched with the appointed dimension parameter.

S103: based on a CMYK printing color mode, overlapping pixel points of a foreground image and a background image to generate an identification image, and expressing the pixel points of the identification image by utilizing CMYs synthetic color and K color.

In a preferred embodiment, in order to facilitate automatic identification, an 'L' -shaped boundary identification pattern is arranged at four corners of the identification image; and the foreground image, the background image and the identification image document are stored in a TIF format. By adopting the TIF, the original image layer can be retained to the maximum extent, the distortion of the image is reduced, and the quality of image output is improved. Alternatively, in addition to the TIF format, the storage may be performed using a format such as JPG under the condition that the image quality is ensured, and the technical effects of the present invention may also be achieved.

In a specific embodiment, the specific generation steps of the identification image are as follows: a buffer area of the same size and size as the received identification image is generated as a storage area of the identification image, and each pixel point is set to gray, which is expressed by a composite color of CMY.

And taking out the foreground image in the TIF file, copying each pixel point to a pixel point corresponding to the synthesized image one by one according to the sequence of the line or the main sequence, setting the target pixel point to be black if the current pixel point of the foreground image is black during copying, and keeping the pixel point to be gray if the current pixel point of the foreground image is white. Black is represented by a composite color of CMY.

Taking out the background image in the TIF file, copying each pixel point one by one to the pixel point corresponding to the synthesized image according to the sequence of lines or columns as a main sequence, and if the current pixel point of the background image is black during copying and the current pixel point of the target image is also black at the moment, keeping the black of the target pixel point unchanged, but using K color to express the target pixel point; if the current pixel point of the background image is black and the current pixel point of the target image is white at the moment, the target pixel point keeps gray unchanged, but is represented by K color; and if the current pixel point of the background image is white, keeping the pixel point on the identification image unchanged. A schematic diagram of generating the identification image after the foreground image and the background image are superimposed is shown in fig. 2.

In a specific embodiment, the specific representation mode of the pixel points of the identification image is as follows: expressing white pixel points of the intersection of the foreground image and the background image by using CMY synthesized gray; expressing that pixel points in the foreground image are black and corresponding to pixel points in the background image are white by utilizing black synthesized by CMY; black pixel points of the intersection of the background image and the foreground image are represented by black of K color; and expressing that the pixel points in the background image are black and the pixel points corresponding to the pixel points in the foreground image are white by using K-color gray. By means of the arrangement of the CMY composite color and the K color, a foreground image of the CMY composite color can be visible under normal light, a background image of the K color can be visible under infrared light, and the background image is represented and hidden in the foreground image by the CMYK colors with the same color and different colors, so that the anti-counterfeiting effect is achieved.

In a specific embodiment, each color of CMY is transparent under infrared light recognition, and similarly, a composite color of three colors of CMY cannot be read in the infrared light recognition device, and the K color contains carbon in the material, and exhibits an absorption characteristic for infrared light under infrared light irradiation, so that the identification can be read in the recognition device.

S104: outputting the document with the identification image using a printing apparatus. By virtue of the above configuration of the pixel points of the identification image, a document with the identification image can be output by printing at one time by a general color printer apparatus.

In a specific embodiment, the printer is a color ink jet printer or a color laser printer; the printing paper adopts white common printing paper, and the natural color of the printing paper is obviously poor in visual identification with the printed gray color.

In a specific embodiment, the gray colors in the identification image, including the gray color synthesized by CMY and the gray color formed by K, have similar color stimulus values, so that the background image is better hidden under normal illumination, and the foreground image is better filtered under infrared illumination. For different printers, the color stimulus values of gray formed by CMY composite and K are different, resulting in a possibility that the printing effect may be different, and thus deviation correction of CMY values is required. In the print drive extension module, printers of different brands need to be processed respectively, and CMY weight coefficients are configured reasonably. By means of the configuration, the identification image in the document can be clearer, the background image is better hidden in the foreground image under the common light, and the anti-counterfeiting effect is better realized.

Fig. 3 shows a flow chart of an authentication method for a protective document according to an embodiment of the invention. The method specifically comprises the following steps:

s301: and carrying out standardized processing on the imaging of the identification image on the document to be identified under infrared illumination to obtain a background image in the identification image. The method comprises the steps of standardizing imaging of an identification image under infrared illumination, rotating, translating and scaling the image by taking a boundary pattern as a basis, restoring the imaging, and carrying out binarization processing on the image, wherein the average value of all pixel gray levels of the identification image is taken as a standard, the pixel gray level in the image which is smaller than the average value is set to be white, and the pixel gray level which is larger than the average value is set to be black. The MD5 value and signature image in the background image are obtained, and as shown in fig. 4, the identification image shows the background image under infrared illumination and does not show the foreground image under normal illumination.

S302: converting the current document into electronic format, calculating its MD5 value, comparing with MD5 value in background image, and judging whether the contents of the document are identical.

In a specific embodiment, when the document to be authenticated has splicing traces and the authenticity of the document content is questioned, the current page image is converted into a text, and the MD5 value of the text is calculated. Manually comparing the calculation result with the MD5 in the infrared image, and if the calculation result is the same as the MD5 in the infrared image, determining that the content is real; if not, the result is not true and is inconsistent with the issued content. Whether the text in the document is consistent can be directly identified through the MD5 value of the text.

S303: and carrying out similarity comparison on the background image restored under the infrared light and the original background image, and calculating the similarity value of the background image and the original background image. Through the judgment of the similarity, whether the background image in the identification image is consistent with the original identification image or not can be judged, so that whether the identification image is forged or not can be judged.

S304: the document to be authenticated is true only if the MD5 values are consistent and the similarity value is greater than the similarity threshold. The authenticity of the document is judged through the similarity of the images and the MD5 value, the MD5 value can judge whether the text content of the document is real, and the similarity can judge whether the identification image of the document is real. The authenticity of the document can be effectively judged by combining the two.

In a specific embodiment, the similarity between the foreground image and the original foreground image under the common light can be compared, the similarity value between the foreground image and the original foreground image is calculated, and the authenticity of the identification image is further verified by judging by using the similarity threshold value.

In a preferred embodiment, the similarity threshold may be set to 90%, and the setting of the similarity threshold may visually determine whether the images are consistent by using data, thereby determining the authenticity of the document. It should be appreciated that the similarity threshold may be set to a higher or lower value according to the actual application scenario to meet the requirements of different application scenarios.

FIG. 5 shows a block diagram of an information management system according to one embodiment of the invention. The system comprises a client 501, an image acquisition terminal 502 and a remote server 503. The client 501 and the image acquisition terminal 502 are respectively connected with the remote server 503. The information management system realizes the management of the business handling process and the result of the document issuing mechanism and realizes the closed loop of document generation and use. Each document is generated and printed out on the system and those not generated on the system will not have the document protection and authentication features.

In a particular embodiment, the client 501 is configured for document management using the method described in FIG. 1. The client 501 has a printer extension driver activation function, causing the identification image print extension function to be activated. The document is required to be audited in the information management system before being issued, the printing expansion function is automatically activated after the audit is passed, and the management module displays the activation state; and if the printing expansion function fails, the printing expansion function is not activated. Once the document has been approved, no further modifications can be made. And the document can be printed and output after passing the audit. When the document passing the audit is processed and the document not passing the audit is processed, the system automatically inactivates the printing expansion function.

In a preferred embodiment, when installing the print driver extension module, the information system user digital certificate is provided and only the legitimate user can activate the extension module. The system needs to check the validity of the digital certificate every time the user enters the information system, and when the annual audit of the organization to which the user belongs fails or other abnormal conditions occur, the digital certificate is set to be in an invalid state. By means of the digital certificate, the counterfeit of the document by an unqualified institution by using the system can be avoided.

In a specific embodiment, image capture terminal 502: the method is configured to be used for carrying out standardized processing on the imaging of the identification image on the document to be identified under the infrared illumination to obtain a background image in the identification image.

In a preferred embodiment, a micro infrared camera is adopted and an infrared LED fill light is configured for infrared image acquisition, acquired image information is transmitted to a mobile phone through a camera USB interface through OTG conversion connection, and an infrared image is displayed by means of a mobile phone display screen. The infrared camera, the infrared lamp and the smart phone jointly form an infrared image acquisition terminal.

In a preferred embodiment, the wavelength of the infrared camera is selected to be more than 1000nm, and the wavelength of the infrared LED lamp is selected to be more than 1000nm, so that non-infrared light can be filtered better; the infrared camera can image at a micro distance (8-18 cm). By means of reasonable wavelength selection, non-infrared light can be better filtered, and a better imaging effect is obtained.

The remote server 503: the method described with reference to fig. 3 is configured to identify whether the document is authentic. By judging the image identified under infrared light and identifying the authenticity of the identification image and the authenticity of the document content based on the MD5 value and the similarity, the authenticity of the document can be effectively judged by comprehensive judgment of the two aspects.

Embodiments of the present invention also relate to a computer-readable storage medium having stored thereon a computer program which, when executed by a computer processor, implements the method above. The computer program comprises program code for performing the method shown in the flow chart. It should be noted that the computer readable medium of the present application can be a computer readable signal medium or a computer readable medium or any combination of the two.

The invention utilizes the printing color technology of CMYK to superpose and fuse the foreground picture and the background picture for document anti-counterfeiting to generate the identification image, the identification image has the characteristic that different images can be observed under different light sources, the foreground image can be seen under a common light source, such as LOGO of a mechanism, but the background image can not be seen; under infrared illumination, background images such as handwritten signatures and MD5 values of file contents are seen, but foreground images are not seen. The technology can realize the anti-counterfeiting identification of the document, and is applied to a closed loop system for document generation and use, thereby avoiding the situation that the document cannot be identified due to counterfeiting and tampering.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the invention herein disclosed is not limited to the particular combination of features described above, but also encompasses other arrangements formed by any combination of the above features or their equivalents without departing from the spirit of the invention. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. A method for generating a protective document, comprising the steps of:

s1: acquiring a document to be protected in an electronic format;

s2: determining a foreground image of the document to be protected based on the document to be protected, calculating an MD5 value of the document to be protected in the electronic format, converting the MD5 value into a background image, and respectively acquiring pixel point information of the foreground image and the background image;

s3: based on a CMYK printing color mode, overlapping pixel points of the foreground image and the background image to generate an identification image, and expressing the pixel points of the identification image by utilizing CMYs synthetic color and K color;

S4: outputting the document with the identification image by using a printing device;

the specific representation mode of the pixel points of the identification image is as follows:

expressing white pixel points of the intersection of the foreground image and the background image by using CMY synthesized gray;

and expressing that the pixel points in the background image are black and the pixel points corresponding to the pixel points in the foreground image are white by using K-color gray.

2. A method of generating a document for protection as claimed in claim 1 wherein the foreground image includes the LOGO of the issuing authority of the document to be protected and the background image further includes the signature of the issuer.

3. A generation method for a protective document according to claim 1, characterized in that the four corners of the identification image are provided with "L" -shaped boundary identifications for automatic recognition.

4. A method of generating a protective document as claimed in claim 1, characterised in that the identification image document is in TIF format.

5. A method of generation for a protective document as claimed in claim 1, wherein the printing apparatus comprises a colour inkjet printer or a colour laser printer.

6. A method of authentication for a protective document, comprising the steps of:

standardizing imaging of a marker image on a document to be identified, which is generated by the method of any one of claims 1-5, under infrared illumination to obtain a background image in the marker image;

converting the current document into an electronic format, calculating the MD5 value of the current document, comparing the MD5 value with the MD5 value in the background image, and judging whether the contents of the document are consistent;

the document to be authenticated is true only if the MD5 values are consistent and the similarity value is greater than a similarity threshold.

7. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a computer processor, carries out the method of any one of claims 1 to 6.

8. An information management system, comprising:

The client side comprises: configured for document management using the method of any one of claims 1 to 5;

an image acquisition terminal: the method comprises the steps that imaging of an identification image on a document to be identified under infrared illumination is configured and used for carrying out standardization processing, and a background image in the identification image is obtained;

the remote server side: configured to authenticate the document as authentic using the method of claim 6;

9. The information management system according to claim 8, wherein the image acquisition terminal comprises an infrared camera, and an infrared LED light supplement lamp is arranged on the infrared camera.

10. The information management system according to claim 9, wherein the wavelength of the infrared camera is 1000nm or more, and the wavelength of the infrared LED fill light is 1000nm or more.

11. The information management system of claim 9, wherein the infrared camera is connected to a mobile phone or a computer for displaying an infrared image.